A versatile, efficient route to A-ring aromatic trichothecanes has been developed. The synthetic scheme which was developed will be used to elaborate various 12,13-spiroepoxide derivatives which have different A-ring substituents and C-ring substituents. A similar route, through a (3,3) sigmatropic rearrangement, will be employed for the synthesis of aliphatic A-ring trichothecanes. Simple polyfunctional trichothecane analogs will also be studied. These latter studies will elaborate upon the discovery that dimethyl 5,6-exo-oxido-7-oxabicyclo (2.2.1) hept-2-ene-2,3-dicarboxylate and dimethyl 5,6-bis(acetoxmethyl)-7-oxabicyclo(2.2.1) hepta-2,5-diene-2,3-dicarboxylate showed significant cytotoxic activity in the 9-KB and L-1210 tissue culture systems, respectively. BIBLIOGRAPHIC REFERENCE: W.K. Anderson, E.J. LaVoie, and J.C. Bottaro, J. Chem. Soc., Perkin Trans, I., in press, (1976). "The Use of 2,3-Dichloropropene and 1,3-Dichloro-2-butene as Synthons for Heterocyclic Compounds: The Synthesis of 2-Methyl-benzo(b)furans, 2-Methylbenzo(b)Thiophenes, and 4-Methyl-3-Chromene."